Lock guard



Au 4, 1936. w. M. BARRY 2,049,796

LOCK GUARD Filed June 4, 1955 INVENTOR liiiiir 1% Barry @-%uwm ATTORNEY Patented Aug. 4, 1936 warren sr rss PATENT OFFEQE LOCK GUARD 1 Claim.

This invention relates to improvements in door locks, and it is the principal object of my invention to provide locks of all types with means to make the lock substantially jimmy-proof.

It is a well known fact, that almost any door in ordinary use, including the metal covered fireproof doors etc., can be quite readily opened by means of a jimmy forcing the door apart from its jamb sufliciently to allow the projecting bolt or latch of a dead lock to be forced over the striking plate. This is positively prevented by my novel lock-guard composed of interchanging, interengaging and interlocking members, which, while not impeding the opening and closing of the door in the customary manner, will engage one another as soon as a jimmy or other like instrument is inserted between the door and the jamb to prevent the door from being forcibly opened, as these members will interlock the tighter the harder they are forced.

Another object of my invention is the provision of a lock-guard of a comparatively simple and inexpensive construction yet durable and highly efficient in use, and one which can be readily attached to any door without material changes.

A further object of my invention is the provision of a lock guard composed of an angular door attached locking member and a locking member attached to the jamb having overlapping edges somewhat thicker than their other portions facing each other in such a manner as to positively engage at the moment a jimmy is inserted between the door and the jamb.

A still further object of my invention is the provision of a lock guard the members of which are secured to the door and its jamb respectively by means of screws which cannot be tampered with.

These and other objects and advantages of my invention will become more fully known as the description thereof proceeds, and will then be more specifically defined in the appended claim.

In the accompanying drawing forming a material part of this disclosure:

Fig. 1 is a longitudinal section through a door and its jamb equipped with a lock guard constructed according to my invention.

Fig. 2 is a fragmentary View of the outer face of a door and jamb to which my lock guard is attached.

Fig. 3 is a section on line 3-3 of Figure 1.

As illustrated, a door ll! of any conventional type, and equipped with the customary locks ll, I2 and knobs I3, has attached to the outside thereof even with its edge and about centered over the lock and bolt, an attachment it having preferably substantially the form of an angle iron, L-shaped in cross-section and an inwardly and downwardly extending abutment flange l5.

One branch of the angle iron l has integrally made therewith interiorly threaded sockets I6 embedded into the material of the door and extending therethrough, into which are screwed machine screws H from the inner side of the door to firmly secure the attachment M to the door tamper-proof, so that it cannot be removed therefrom from the outside.

The latch I8 or bolt of the lock engages the conventional keeper or strike plate l 9 in the usual manner. The material of the door stop 20 or portion of the jamb which acts as such door stop is cut-away, as indicated at 2|, for a suflicient epth to accommodate the projecting door attachment M to thus allow the normal operation of the door.

To the jamb 20 a plate 22 is attached and secured thereto by one-way screws 23 of any well known type, said plate having formed therewith an abutment edge 24 adapted to engage the abutment flange l5 of member M in the closed position of the door when an attempt is made to jimmy the door.

It will be clear that with door jambs of the type that have separate door stops which may be removed from the outside, it will be necessary to use screws long enough to project through the door stop and to firmly engage the solid portion of the jamb.

In use, when the door jamb plate 22 and the member M are attached as above described, and the door is closed and locked, plate 22 and member M will prevent any tampering with the latch or bolt to move them out of their keeper engaging position. However, as soon as an attempt is made to jimmy the door, the inwardly directed abutment flange of member l5 and of member 22 will engage one another and prevent the door from being opened, and the harder the jimmy is worked, the tighter both abutment flanges will look.

It will be understood that I have described and shown the preferred form of my invention only as one example of the many possible ways to practically construct the same, and that I may make such changes in the general arrangement thereof and in the construction of its minor de tails, as come within the scope of the appended claim without departure fro-m the spirit of my invention and the principle involved.

t will also be understood, that my device is particularly well adapted to prevent tampering with the spring locks by the insertion of a knife blade or flexible object by means of which the bolt of the lock may be thrown out of its locking position.

Having thus described my invention, what- I claim as new and desire to secure by Letters Patent is:

In a look guard for doors, an attachment to the door substantially L-sl1aped in cross-section, an inwardly extending abutment flange formed with said attachment, interiorily threaded sockets integrally made with one of the branches of the L and embedded into the material of the door and partly extending through the same, machine screws screwed into said sockets from the inner side of the door to secure the attachment firmly and tamperproof to the door, protected against removal from the outside, and a plate attached to the door jamb by means of one-way screws, and an interlocking edge formed with said plate adapted to engage the abutment flange of the L-attachment in the closed position of the door, if an attempt is made to jimmy the door to prevent spreading of the door from its jamb and opening of the door;

WALTER M. BARRY. 

